The use of hindered phenols, such as 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-para-cresol, has been well known for their thermal/oxidation stabilizing properties in a variety of lubricant, polymer and elastomer applications.
Benzotriazole or a substituted benzotriazole compound reacted with an alkyl aldehyde and dialkylhydrogen phosphites provide products which improve the load-carrying, antiwear properties of lubricant oils and greases. These reactants are disclosed in U.S. Pat. No. 4,626,368 which issued to Cardis on Dec. 2, 1986. Amine coupled condensation products of hindered phenols and phosphites are disclosed in U.S. Pat. No. 5,288,418 which issued to Farng et al. on Feb. 22, 1994. These products were found to be effective antioxidant/antiwear additives for lubricants. These patents are incorporated by reference herein.
Although commercially available hindered phenol and aromatic amine antioxidants provide excellent oxidation protection, it is desirable to have compounds which can provide for even greater oxidation protection while providing for additional antiwear properties as well as other multifunctional properties.
Therefore, what is needed is a novel lubricant additive compound with exceptional antioxidant activity combined with additional antiwear properties as well as other beneficial multifunctional properties for incorporation into improved lubricant compositions.